Improvement in chimney-caps



J. CLARK.

Chimney Cap.

'Patented sept'. 5,1854.

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UNITED STATES PATENT OFFICE.

JOHN CLARK, OF VASI'IINGTON, DISTRICT OF COLUMBIA.

IMPROVEMENT IN CHlMNEY-CAPS.

Specification forming part of Letters Patent No. 11,640, dated September 5, 1854.

To all whom it 11i/ty concern:

Be it known that I, JOHN CLARK, of the city and county of Washington and -District of Columbia, have invented a new and useful Improvement in the Construction of Chimney- Caps; and I do hereby declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming part of this specification.

The nature of my invention consists in so constructing chimney-caps as to close the surface presented to the current of air, and at the same time form an egress for the smoke to escape on the opposite side, as hereinafter described.

The same letters indicate the same parts in both the figures.

To enable others skilled in the art to make and use my improved chimney-caps, I will proceed to a description of the same in detail.

Figure l represents a viewin perspective of a chimney-cap secured to a fragment of a chimney. Fig. 2 is a vertical section of the same, taken through the line x t ot' Fig. l.

A represents the cap, which may be constructed of eithercast or sheet metal, as found expedient. On the four opposite sides of this cap, as represented in the accompanying drawings, are formed apertures c, embracing nearly the entire side of the cap. Tothese apertures are tted, respectively, doors or valves E, hinged on their lower sides at j', so that the egress for the smoke may be at the top of the cap, and thus prevent the undue accumulation in the cap. In order that the valve opposite to that which is closed by the current of air shall open to permit the escape of the smoke, I have connected them in pairs by cross-rods c, which rods serve also to retain them in their proper upright position with respect to the cap. That these doors or valves shall assume a position When not acted upon by a current of air equidistant from the face of the cap, I have provided balance-Weights` D, which are secured to the lower sides of the valves E by rods e. rlhese weights may be arranged either on the exterior of the valve, as shown in Fig. 1, or on the interior, as represented in Fig. 2, or they can be dispensed with entirely by extending the lower end, as indicated by dots in Fig. l, making the valve a balance-valve. Thus it will be seen that when the valvesE are forced against the sides of the cap A, as indicated by the arrows, Figs. l and 2, the corresponding valves on the opposite sides, being connected in pairs byrods 0 will be thrown open to their extreme width, thus permitting the smoke free egress on the sides opposite to those receiving the blast. By thus connecting the valves in pairs it will readily be perceived that whether the valves are being acted upon by a current of air or have assumed by the weights D their respective positions equidistant from the faces ot' the cap, the amount of egress for the smoke will at all times be the same. I do not conne myself to any particular form, but would state that it may consist of as many sides as found desirable.

Having thus fully described my improved mode of constructing chimney-caps, what I claim therein as new, and desire to secure by Letters Patent of the United Stat-es, is as follows:

Disclaiming the invention ol' chimney-caps with pendent valves, I claim constructing chimneycaps having balance compensating valves E E E, Fig. l, with lever e and weight D, or its equivalent g g, together with the 

